source: misc/scripts/minify_if_changed.sh @ 744

#!/bin/sh
SOURCE=$1
ONLY_IF_MINIFIED_ALREADY_EXISTS=$2
DESTINATION=`echo $1|sed 's/\.[A-Za-z]*$/.min\0/g'`
MD5SUM=`which md5sum`
MD5_CURRENT=
MD5_NEW=
TMP_FILE=~/tmp/minified

# got a parameter?
if [ ! $1 ]; then
        echo "Usage: "$0" <input file> [only create if a minified already exists]"
        echo "Example: "$0" bla.js 1"
        exit;
fi

# does the input file exist?
if [ ! -f $1 ]; then
        echo "Usage: "$0" <input file> [only create if a minified already exists]"
        echo "Example: "$0" bla.js 1"
        echo "error: could not find "$1
        exit;
fi

# does the destination exist?
if [ -f $DESTINATION ]; then
        # yes, create an MD5 sum
        MD5_CURRENT=`$MD5SUM -t $DESTINATION | sed 's/ .*$//g'`
elif [ $ONLY_IF_MINIFIED_ALREADY_EXISTS ]; then
        # no need to continue
        exit;
fi

# minify sourcefile
java -jar ~/apps/yuicompressor-2.4.2/build/yuicompressor-2.4.2.jar $SOURCE > $TMP_FILE

# determine the MD5 hash of the generated file
MD5_NEW=`$MD5SUM -t $TMP_FILE | sed 's/ .*$//g'`

# do the MD5 hashes differ?
if [ "$MD5_CURRENT" != "$MD5_NEW" ]; then
        cp $TMP_FILE $DESTINATION
        echo ".created minified version of "$SOURCE" ("$MD5_CURRENT" > "$MD5_NEW")"
fi

# remove temp file
if [ -f $TMP_FILE ]; then
        rm $TMP_FILE > /dev/null
fi